The Oasis Quick-Change Red 50 GPD Thin Film Filter 033664-001 is meant for use on all Oasis Reverse Osmosis water coolers and most new style Oasis point-of-use and under-counter filter systems. This reverse osmosis filter, through the most advanced method of water filtration, gives you the purest drinking water. Water is pushed through the filters fine membrane under pressure so that nothing passes through the membrane except for pure water molecules. The result is a difference you can taste.